RE: expanding a list
- To: mathgroup at smc.vnet.net
- Subject: [mg42610] RE: [mg42593] expanding a list
- From: "Harvey P. Dale" <hpd1 at nyu.edu>
- Date: Fri, 18 Jul 2003 05:25:03 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Alan:
This should do it:
Flatten[Table[#[[1]],{#[[2]]}]&/@Transpose[{plist,flist}]]
Best,
Harvey
Harvey P. Dale
University Professor of Philanthropy and the Law
Director, National Center on Philanthropy and the Law
New York University School of Law
Room 206A
110 West 3rd Street
New York, N.Y. 10012-1074
-----Original Message-----
From: Alan Kelly [mailto:Alan.Kelly at tcd.ie]
To: mathgroup at smc.vnet.net
Subject: [mg42610] [mg42593] expanding a list
Hi all,
I believe that this is a rather elementary question, but I am not
aware of a simple, elegant and efficient solution. I have searched
the MathGroup archive, but with no success.
I have two lists - both of the same length. The first contains a
list of probabilities. For example, suppose the list length is 4
(although in practice it would be much longer) and is of the
following form:
plist = {0.252, 0.252, 0.257, 0.235}.
The second contains a list of integers:
flist = {7,5,6,4}.
I wish to take the first element of plist and replicate that value
using the first element of flist. Similarly for the remaining
elements.
I should finish with a list of length 7+5+6+4 or 22.
Any suggestion please.
Many thanks,
Alan Kelly
Trinity College Dublin